The trial of Karma Samdrup came after he spoke up for his two brothers, also activists, who were detained after accusing local officials in eastern Tibet of poaching endangered species. Authorities in tightly controlled Tibet are extremely sensitive to social activism and criticism, either explicit or implied.The cases come amid increased repression of Tibetan intellectuals, an echo of the massive security crackdown that followed rioting in the capital, Lhasa, in 2008..

In addition to the prison sentence, Karma Samdrup was stripped of his political rights for five years and fined 10,000 yuan ($1,500) after a three-day trial with sessions that lasted until midnight, lawyer Pu Zhiqiang told The Associated Press.

"I want to appeal, I have to appeal," Karma Samdrup's wife, Zhenga Cuomao, (Dolkar Tso) quoted him as saying after the verdict was handed down at the court in remote Yanqi county in the Xinjiang region adjoining Tibet.

Phones at the court rang unanswered Thursday night after the verdict was announced.

Pu complained of irregularities in the trial, including witnesses who testified against Karma Samdrup that defense attorneys did not recognize.

Karma Samdrup's wife and lawyers have accused police of torturing him in custody. In his statement to the court, he said that during months of interrogation, officers beat him, deprived him of sleep for days and drugged him with a substance that made his eyes and ears bleed, they said.

"I cannot recognize him anymore. I can only recognize his voice," Zhenga Cuomao said. "He used to be so tall, so strong ... now he looks so fragile."

The charges against Karma Samdrup - named philanthropist of the year in 2006 by state broadcaster CCTV - date back to 1998 but were not pursued until this year.

Karma Samdrup's younger brother, Chime Namgyal, is reportedly serving a 21-month sentence in a labor camp on the vague charge of harming national security. His older brother, Rinchen Samdrup, was scheduled to be tried on a similar charge this week, but that date has been postponed.